Digital rights management (DRM) is a technology used to protect and control the distribution of content, such as music files, video files, and other content. In DRM, content is encrypted with a cryptographic key, whereby the cryptographic key can also be used to decrypt the content. In order for a user to decrypt and access the content, the user must have access to a license that is associated with the content. Generally, a license can grant different access rights to the content depending on the permissions defined by a license provider. For example, the license may limit the content (e.g., a music file) to be played for a limited number of times.
In traditional DRM technologies, the cryptographic key used to decrypt the content is stored only in the license. The license can be hacked and the cryptographic key can be easily extracted from the license. If the cryptographic key is compromised, an unauthorized user can decrypt the content without the license and thereby access the content without limitations. As a result, there is a need to further improve the protection of content.